Rosen & Barkin's 5-Minute Emergency Medicine Consult (30 page)

• Exercise stress testing:
  
  • Not appropriate if active chest pain with moderate to high likelihood of ischemia
    
  • Imaging stress test (sestamibi, thallium, or echo) if baseline ECG abnormalities
    
  • Early positive (within 3 min) concerning for UA
    
• Coronary angiography:
  
  • Gold standard of diagnosis for CAD
    

• Anxiety and panic disorders
  
• Aortic dissection
  
• Biliary colic
  
• Costochondritis
  
• Esophageal reflux
  
• Esophageal spasm
  
• Esophagitis
  
• GERD
  
• Herpes zoster
  
• Hiatal hernia
  
• Mitral valve prolapse
  
• Musculoskeletal chest pain
  
• MI
  
• Myocarditis
  
• Nonatherosclerotic causes of cardiac ischemia
  
  • Coronary artery spasm
    
  • Coronary artery embolus
    
  • Congenital coronary disease
    
  • Coronary dissection
    
  • Valvular disease: AS, AI, pulmonary stenosis, mitral stenosis
    
  • Congenital heart disease
    
• Peptic ulcer disease
  
• Pericarditis
  
• Pneumonia
  
• Psychogenic
  
• Pneumothorax
  
• Pulmonary embolism
  

TREATMENT

• IV access
  
• Aspirin
  
• Oxygen
  
• Vital signs and oxygen saturation
  
• Cardiac monitoring
  
• 12-lead ECG, if possible
  
• Sublingual nitroglycerin
  

• IV access
  
• Oxygen
  
• Cardiac monitoring
  
• Vital signs and continuous oxygen saturation
  

• All patients with chest pain in which cardiac ischemia is a consideration should receive an aspirin upon arrival to the ED
  
• Sublingual nitroglycerin: If symptoms persist after 3 sublingual doses, suggestive of UA, AMI, or noncardiac etiology
  
• Pain control
  
• Anticoagulation
  

• Aspirin: 325 mg PO (chewed) or 81 mg × 4 (chewed)
  
• In patients with aspirin allergy: Clopidogrel (Plavix) 300--600 mg PO, also consider prasugrel 60 mg PO or 180 mg PO ticagrelor
  
• Dual antiplatelet therapy should be given to patients with UA at medium to high risk who have been selected to have invasive strategy such as catheterization or surgery
  
• Nitroglycerin:
  
  • 0.4 mg sublingual
    
  • 5–10 μg/min IV USE NON-PVC tubing, titrating to effect
    
  • 1–2 in of nitro paste
    
  • Hold for low BP (can severely drop BP)
    
  • Beware if pt has history of erectile dysfunction and use of phosphodiesterase inhibitors like sildenafil (Viagra) or tadalafil (Cialis) can last 48 hr
    
• Morphine
  
  • 4 mg IV, titrate to relief of pain assuming no respiratory depression and SBP >90
    
• Consider beta blocker
  
  • Metoprolol: 25—50 mg PO or 5 mg IV q5–15min for refractory HTN and tachycardia
    
  • Contraindicated in reactive airway disease, active CHF, bradycardia, hypotension, heart block, cocaine use
    
  • Does not necessarily need to be given while patient is in ED, suggested benefit within 24 hrs of AMI
    

Anticoagulation

• Does not alter mortality
  
  • Consider conferring with cardiology prior to anticoagulation
    
  • Heparin: 60 U/kg IV bolus, then 12 U/kg/hr (goal PTT 50–70)
    
  • Enoxaparin: 1 mg/kg SC q12 or q24 if Cr clearance <30mL/min
    
• Glycoprotein IIb/IIIa inhibitors: Primary benefit en route to cath
  
  • Eptifibatide (Integrilin): 180 μg/kg bolus IV over 1–2 min, then 2 μg/kg/min up to 72 hr
    
  • Tirofiban (Aggrastat): 0.4 μg/kg/min for 30 min, then 0.1 μg/kg/min for 48—108 hr
    
  • Abciximab (Reopro): 0.25 mg/kg IV bolus, then 0.125 μg/kg/min, maximum dose 10 μg/min for 12 hr
    
  • Bilvalirudin, fondaparinux
    
• Patients at risk for high risk for bleeding include the elderly, female, anemic, chronic renal failure
  

FOLLOW-UP

• Patients with UA require admission to the hospital
  
• Early intervention with cardiac catheterization likely decreases mortality in patients with elevations in cardiac enzymes, persistent angina or hemodynamic instability
  
• Patients with unclear diagnosis likely would benefit from admission to ED observation unit or hospitalization for serial cardiac enzymes, ECG and stress testing/catheterization
  

• Patients with stable angina
  
• Patients who are enzyme/stress testing or cath negative
  

Patients with stable angina or workup negative chest pain should follow up with their PCP or cardiologist within several days of ED visit.

• History is the most important factor in differentiating unstable from stable angina or noncardiac pain
  
• All patients with chest pain or symptoms concerning for a cardiac etiology should have an immediate ECG
  
• It the initial ECG is normal or unchanged, do serial ECGs 10–30 min apart
  
• A single set of negative cardiac enzymes may not rule out ACS in a patient with chest pain
  
• Women, diabetics, ethnic minorities, and patients >65 yr require a low threshold for ACS workup as they often have atypical presentations
  

• 2012 Writing Committee Members, Jneid H, Anderson JL, et al. 2012 ACCF/AHA focused update of the guideline for the management of patients with unstable angina/Non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines.
  Circulation.
  2012;126(7):857–910.
  
• Marx JA, Hockberger RS, Walls RM, eds.
  Rosen’s Emergency Medicine: Concepts and Clinical Practice
  . 7th ed. Philadelphia, PA: Mosby Elsevier; 2010.
  
• Mistry NF, Vesely MR. Acute coronary syndromes: From the emergency department to the cardiac care unit.
  Clinics.
  2012;30:617–627.
  
• Swap C, Nagurney JT. Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes.
  JAMA.
  2005;294:2623–2949.
  

See Also (Topic, Algorithm, Electronic Media Element)

• ACS Myocardial Infarction
  
• ACS Coronary Vasospasm
  
• Cardiac Testing
  

CODES

• 411.1 Intermediate coronary syndrome
  
• 413.1 Prinzmetal angina
  
• 413.9 Other and unspecified angina pectoris
  

BASICS

• Spontaneous episodes of chest pain due to coronary artery vasospasm in the absence of increase in myocardial oxygen demand in either normal or diseased coronary vessels
  
• Also known as Prinzmetal angina or variant angina, originally described in 1959
  
• Most common in younger patients and men
  
• Usually
  occurs in patients without cardiac risk factors or coronary artery disease
  
• Risk factors:
  
  • Smoking (up to 75% of cases)
    
  • Hypertension
    
  • Hypercholesterolemia
    
  • Diabetes mellitus
    
  • Cocaine use
    

• Abnormal vasodilator function in coronary arteries typically endothelial in origin
  
• High prevalence of microvascular and epicardial vessel involvement
  
• Defined by 3 types
  
  • Focal: Localized, often at or near a site of stenosis of a single artery
    
  • Multifocal: 2 or more segments of the same artery
    
  • Multivessel: Involving different coronary arteries
    
• Unopposed α sympathetic stimulation
  
• Sympathetic stimulation by endogenous hormones may cause vasoconstriction.
  
• Conversely, also associated with increased vagal tone or withdrawal from vagal tone as proven with acetylcholine provocative testing
  
• Hypersensitivity of coronary arteries due to mediators of vasoconstriction
  
• Endothelial dysfunction possibly from genetic mutations in nitric oxide synthase
  
• Newer research suggests potential increase ρ-kinase activity in smooth muscle cells